Method to form a pattern of functional material on a substrate by treating a surface of a stamp

Abstract

The invention provides a method to form a pattern of functional material on a substrate. The method uses an elastomeric stamp having a relief structure with a raised surface and having a modulus of elasticity of at least 10 MegaPascal. At least the raised surface of the stamp is treated by exposing the stamp to heat, radiation, electrons, a stream of charged gas, chemical fluids, chemical vapors, and combinations thereof, to enhance wettability of the surface. A composition of the functional material and a liquid is applied to the relief structure and the liquid is removed to form a film on the raised surface. The elastomeric stamp transfers the functional material from the raised surface to the substrate to form a pattern of the functional material on the substrate. The method is suitable for the fabrication of microcircuitry for electronic devices and components.

1 . A method to form a pattern of functional material on a substrate comprising:
 a) providing an elastomeric stamp having a relief structure with a raised surface, the stamp having a modulus of elasticity of at least 10 MegaPascal;   b) treating at least the raised surface of the elastomeric stamp;   c) applying a composition comprising the functional material and a liquid to the relief structure;   d) removing the liquid from the composition on the relief structure sufficiently to form a film of the functional material on at least the raised surface; and   e) transferring the functional material from the raised surface to the substrate.   
     
     
         2 . The method of  claim 1  wherein the treating step is selected from the group consisting of plasma treating, ozone treating, corona treating, flame-treating, exposing to ionizing radiation, exposing to ultraviolet radiation, exposing to laser radiation, and combinations thereof. 
     
     
         3 . The method of  claim 2  wherein plasma treating is with a stream of gas selected from the group consisting of helium, argon, hydrogen, oxygen, nitrogen, air, nitrous oxide, ammonia, carbon dioxide, and combinations thereof. 
     
     
         4 . The method of  claim 1  wherein the treating step is by contacting the stamp with a chemical capable of a chemical modifying reaction with one or more reactive components from the stamp. 
     
     
         5 . The method of  claim 3  wherein the chemical is selected from the group consisting of nucleophiles, amines, functionalized analogues of amines, fluorinated amines, functionalized analogues of fluorinated amines, thiols, and functionalized analogues of thiols. 
     
     
         6 . The method of  claim 1  wherein the treating step treats the relief structure of the stamp. 
     
     
         7 . The method of  claim 1  wherein the treating step enhances wetting of the composition on at least the raised surface in step c). 
     
     
         8 . The method of  claim 1  wherein the functional material has a thickness between 0.001 to 1 micrometer on the substrate. 
     
     
         9 . The method of  claim 1  wherein transferring step comprises contacting the raised surface of the stamp to the substrate with pressure less than about 5 lbs./cm 2 . 
     
     
         10 . The method of  claim 1  wherein the functional material is selected from the group consisting of conductive materials, semiconductive materials, dielectric materials, small molecule materials, bio-based materials, and combinations thereof. 
     
     
         11 . The method of  claim 1  wherein the functional material is selected from the group consisting of electrically active materials, photoactive materials, biologically active materials, insulating materials, planarization materials, barrier materials, confinement materials, organic dyes, semi-conducting molecules, fluorescent chromophores, phosphorescent chromophores, pharmacologically active compounds, biologically active compounds, compounds having catalytic activites, photoluminescence materials, electroluminescent materials, deoxyribonucleic acids (DNAs), proteins, poly(oligo)peptides, and poly(oligo)saccharides, and combinations thereof. 
     
     
         12 . The method of  claim 1  wherein the functional material comprises nanoparticles selected from the group consisting of conductive materials, semi-conductive materials, and dielectric materials. 
     
     
         13 . The method of  claim 1  wherein the functional material comprises nanoparticles of a conductive material, the method further comprising step e) sintering the nanoparticles on the substrate to form a continuous film of conductive material. 
     
     
         14 . The method of  claim 13  wherein sintering comprises heating the nanoparticles to temperature up to about 220° C. 
     
     
         15 . The method of  claim 1  wherein the functional material is a conductive material selected from the group consisting of silver, gold, copper, palladium, indium-tin oxide, and combinations thereof. 
     
     
         16 . The method of  claim 1  wherein the functional material is a masking material. 
     
     
         17 . The method of  claim 1  wherein the removing step d) is selected from the group consisting of heating the composition, blowing a gas stream on the composition, evaporating, and combinations thereof. 
     
     
         18 . The method of  claim 1  wherein the elastomeric stamp comprises a layer of a composition selected from the group consisting of silicone polymers; epoxy polymers; polymers of conjugated diolefin hydrocarbons; elastomeric block copolymers of an A-B-A type block copolymer, where A represents a non-elastomeric block and B represents an elastomeric block; acrylate polymers; fluoropolymers, fluorinated compounds capable of polymerization, and combinations thereof. 
     
     
         19 . The method of  claim 1  further comprising forming the elastomeric stamp from a layer of a photosensitive composition. 
     
     
         20 . The method of  claim 1  further comprising forming the elastomeric stamp from a layer of a composition comprising a fluorinated compound capable of polymerization by exposure to actinic radiation. 
     
     
         21 . The method of  claim 20  wherein the fluorinated compound is a perfluoropolyether compound. 
     
     
         22 . The method of  claim 1  wherein the elastomeric stamp further comprises a support of a flexible film. 
     
     
         23 . The method of  claim 1  wherein the substrate is selected from the group consisting of plastic, polymeric films, metal, silicon, glass, fabric, paper, and combinations thereof. 
     
     
         24 . The method of  claim 1  wherein the pattern is transferred onto a layer on the substrate, the layer on the substrate selected from the group consisting of primer layers, adhesive layers, charge injection layers, charge transporting layers, and semiconducting layers. 
     
     
         25 . The method of  claim 1  wherein the liquid comprises one or more compounds selected from the group consisting of organic compounds and aqueous compounds. 
     
     
         26 . An element made by the method of  claim 1 .